float fixed size windows

Operations.hs

@@ -55,8 +55,10 @@ manage w = withDisplay $ \d -> do
     -- before the call to float, because that will resize the window and
     -- lose the default sizing.
 
+    sh <- io $ getWMNormalHints d w
+    let isFixedSize = sh_min_size sh /= Nothing && sh_min_size sh == sh_max_size sh
     isTransient <- isJust `liftM` io (getTransientForHint d w)
-    if isTransient
+    if isFixedSize || isTransient
         then do modify $ \s -> s { windowset = W.insertUp w (windowset s) }
                 float w -- \^^ now go the refresh.
         else windows $ W.insertUp w